Apparatus for producing oxygen.



` B. H. CRAM.

APPARATUS FOR PRODUCING OXYGEN.

. APPLICATION FILED MAY 25. |915. .1,55,045 Patemdsept. 28, 1915.

5 SHErETS-SHET 1.

B. H. CRAM.

APPARATUS FOR PRODUCiNG OXYGEN'.

APPLlcATloN msn MAY 25. 1915.

mme/Jie..

Patented Sept. 28, 1915.

5 SHEETS-SHEET 2.

B. H. CRAM.

I APPARATUS FOR PRODUCING OXYGEN.

APPLICATION FILED MAY 25. 1915. I L. Patented sept. 28,1915.

5 SHEETS-SHEET 5.

A A wm.

@wi/Inmo@ BENJAMIN H. CRAM, F BALTIMORE, LIARYLAND.

APPARATUS FOR'PRODUCING QXYGEN.

Specification of Lettersy Patent. i Patented Sept. 28V, 1915,

Application led May 25, 191,5. Serial No. 30,295.

To all 107mm it may concern 4 Be it known that I, BENJAMIN H. CRAM, acitizen of the United States of America, andv resident of the city ofBaltimore, State of Maryland, have invented certain new and usefulImprovements in Apparatus for Producing Oxygen, of which the followingis a specification. The method of manufacturing oxygen by subjectingpermanganate or manganate of soda, potash or the like to the alternateaction of steam and, air at a high temperature 'is widely known and hasin the past been practised in several instances which are recorded inthe literature of the`art. However, though there is an`extensive demand`for oxygen, ,this process is not practised at the present time becauseit is notV commercially'successful.

: The oxygen obtainedcby this process is married over by superheatedsteam which decomposes thel oxygen compound liberating the oxygen whenthe two are broughtl into contact at a high temperature, and thechemical is regenerated or oxidized by subjecting it to the action ofair, also at a high temperature. The oxygen produced, in order `to becommercially available, must be` of a high percentage of pprity, andinthe past it has been impossible tb produce anything approaching .pureoxygen' by' this process. The diiiiculty is due to the fact that afterpassing air through the .apparatus tooxi dize the permanganate, thepipes and retorts lare filled with air and when steam is introV duced toresume the process of carrying over oxygen, it is necessary either torun this air into the product and thus reduce very/considerably thepercentage of oxygen, 40 for blow it out by the waste or exhaust valveby means of the entering steam. To do this', the steam which is firstbrought in contact with the regenerated permanganate and which thereforecarries a very large percentage of oxygen, must lbe permitted to escape.Theoretically, air can be passed over the permanganate to be regeneratedand superheated steam passed through the apparatus and allowed to escapefor a short pefriod until the apparatus becomes clear of air. Then thesteam is allowed to pass through a condenser and the oxygen is pute intosuitablecarboys, without a loss so considerable as to make the costprohibitive.H However, viewed from a practical standpoint, the periodsare so short and the action electric circuit; and Fig. 7 lshows,

'so rapid that it is difficult to operate the valves and produce thedesired effect `with any degree of regularity, 'or to obtain oXy-4 genof anything approaching uniform purity, so that the operation,whiletheoretically possible, is in fact'impractical f rom a commercialstandpoint and the entire supply of oxygen now required for industrialpurposes 1s made by other methods, as electrolysis or the liquefactionof air. In the present instance, this difliculty has been overcome andan apparatusevolved which'is regular in its operation, producing a gasof a uniform and high-percentage of purity. j This is done by soarranging the connections from the steam and'air supply to the retortsand from the retorts to the condenser and to the discharge that they canbe conveniently controlled by suitable valves to lead the 'steam and airalternately over the desired paths/for exactly the predetermined periodof time, the valves being 4to this end automatically operatedand ytimed.

o Other improvements relate to the provision of a .condensersoconstructed as to prevent the introduction of outside air or air fromthe condensing water to the gas, and numerous refinements alltending togiveA the requisite eiiiciency to make the process commerciallysuccessful. Y

In -the accompanying drawings l have shown so much of an apparatus formaking `oxygen by reduction and regeneration as is .necessary to a fullcomprehension of the improvements which are-the subject of thisinvention. y l

Figures l and 2 taken together ,constitute a diagrammatic showingofthesyst'em, the parts being shifted and rearranged so they can beprojected into the plane of the paper Without overlapping, the objectbeing to show the retorts, gas, air and' steam passages, condensers,etc., arranged in operative relation and as nearly as possible in theorder in which they appear in the operative device; the furnaces do notappear in this diagram; Fig. 3 is a transverse vertical section showingthe furnace, the coils and the retorts in two units of the plant;'Fig. 4

is a section on the line 4, 4 of Fig. 3; Fig. 5 isa diagram of theelectrical system; Fig. 6 is adetail of the cams for controlling the thevalve actuating means. in detail.

Referring to the drawings by numerals; the apparatus consists of ablower or air ranged is passed over the material for the first few/ pump1 delivering air to the air main 2 from which it is ledto an air heatingcoil 3. There are also steam superheating coils 1, 4f', one for eachunit, the units being preferably arranged in pairs. 'Steam is sup pliedat 5 from any suitable source as a steam boiler. The air heating coil 3is connected to the air main by a pipe and this coil isconnected at itsopposite end to a system of piping and automatically controlled valveshereinafter described. rllhese valves control the passage of the airfrom the hot air coil 3 so the heated air may be led through either/oneof the steam superheating coils 4, one of which forms a part of each ofthe units illustrated. Connected Atothe coilsll, 4C by means of a pipe8, in each unit, is a set of retorts 9, and l further provide suitableheating means as the furnace 85 by-Which all the parts are' kept at apredetermined high temperature, for it must be borne in mind -that thereduction and regeneration process by means of which the oxygen'isobtained can only be carried on at high temperatures, and further thatvthe air and all the parts of the apparatus. With Which the steam comesincontact must be heated to prevent loss by condensation. Thek material bythe reduction and regeneration of Which, the oxygen iso produced, isplaced in the retorts and there subjected at intervals, firstto theaction of superheated steam by which, it is reduced, and

y then to the'action of air by Which itis regenerated, both actionstaking place :at a hi'gh temperature. vd

As We have stated, the apparatus is ar- -in pairs of units `or evennumbers of units which operate alternately, that isv the material in theretort of one unit or in the retorts of half the units, is being reducedby a current of superheated steam, While the material in the retort ofthe other unit or the other hallc of the units, is subject to the actionof a current of air, also at a high temperature, and thus regenerated. LAs is understood by those skilled in the art, the steam With the oxygenproduced by the action of the steam on the chemical be-f ing reduced, isled to a suitable container, the steam is condensed, the gas compressedand all the Water Which can possibly be separated fromy the oxygen isremoved, first in an ordinary7 condenser, the principal function ofWhich is to remove the steam, and

then /by 'refrigeration after compression. However, the air which ispassed'cver the charge to regenerate it, and the steam Which secondsWhile the air left in the retorts 'and the rest of the system isbeing'displaced, does not form a part of thesalable product; in fact,if' permitted to enter the condensing system and the containers, itwouldso dilute the gas as to prevent the manufacture of a merchantableproduct, so the air which is passed through the system and even thesteam for the first few seconds of its flow is permitted to escape,either directly or through any suitable device for economizing the heatcontained.

To distribute the heated air and steam to the retorts, there is a systemof automatically controlled valves 7, and to provide for the' escape ofthe air andthe initial steam flovvr in each instance,- as Well as forthe control of the passages by Which the mixed steam and'oxygen are ledto the condenser, a system of automatically controlled valves 10 isused. ln this latter system a pipe 11 isled from the retorts of thefirst unit and a pipe 15 from the retorts of the second unit.k A pipe 16connects the system 10 With the condenser. This pipe is preferablyinclined toward ofi' the'water condensed in the pipe. Referringparticularly to Fig. 2 thepipe 16 leads the steam and oxygen from theretorts to the condenser 17, Where itis passed through small tubes 18which are subject to the action-of a continuous flow of cooling Water,but the Water itself is not brought in contact Witlf the gas. Directcontact of' the Water and gas is objectionable due to the lfact that allwater in its natural state carries a considerable amount of air and thisWater, partlcularly under the low pressure -as a Water-sealed gasometer20, shown asvof a Well-known type. "In the pipe 19 at 21, l.

have shown a T With a valve 22 for use in testing and to permit theescape of the first part of the product in starting to avoid air andother impurities. There is also a valve the condenser tov carryyconditions which exist in this part of the n 23 by which the storage endof the system may beclosed when the valve 22 is opened. At 24 l haveshown a U or depression with a trapped drip 25. Beyond the drip 25 isanother gate valve 26 which may be closed to prevent back How from thegasometer.

vLeading from the gasometer is a delivery pipe 27 with a valve 28 by Wayofvvhichl the oxygen is-carried to a submerged compressor 29 from whichthe gas is passed through a coil 30 submerged in brine in closeproximity to a refrigerating coil 31 from whence the oxygen is led to asuitable container 32 havmg an automatic drip 33. From the containermeans is provided in the Way of valves and delivery outlets 34 forfilling cari boys or s imilar containers with the gas.

eferrlng again to Fig. 1, the steam `su- A ends by pipes 39 and 40constituting a mani- A perheating coils 4 and 4 are connected one toeach of two parallel lines of piping 35 and 36, the connection of 'Lhecoil 4'to the pipe 36 being made by means of a pipe 37, and theconnection of the coil 4 to the pipe 35 being made by means of a pipe38. The two lines 35 and 36 are connected at their fold in the form of aloop or rectangle to one end of which the air coil 3 is connected by apipe 41 and to the other end of which the source of steam 5 is connectedby any suitable means, as a pipe 5. In the pipe 35 on each side of thepipe 38, leading from the steam coil 4, I have shown valves 42 and 43,and in the pipe 36, one on each Side ofl the,- pipe 37 from the {stt-amcoil, I haveshown valves 44 and 45. These valves are automaticallycontrolled to operate at predetermined intervals in the desiredsequence. As illustrated, they -are electrically operated by means ofsolenoids, which, for the sake of convenience, are identified by meansof the numbers applied to the valves, a set ofl two being'provided foreach valve. y

Still referring to Fig. 1, the delivery pipes 11 and 15 leading from theretorts 9 and 9', are, in the form of the invention shown, both led toamanifold 47 having a Waste or exhaust outlets 48, 48, at each end? and adelivery 16 leading from the center of the manifold 47 toward thecondenser 17;` To control the flow from theretorts, four valves 449,50,51 and 52 are provided in the manifold 47, the valves 49 and 50 beingone on each side of the point where the pi'pe 11V joins the pipe 47, andthe valves 51 and 52 being one on each side of the point where the pipe15 vjoins the pipe 47, so that the valves 50 and 51 are one on each sideof the delivery pipe 16.' In 4thisway, the valve svstem 7, including thevalves 42, 43, 44 and 45, controls the flow of air and steam to theretorts 9 and 9, and the valve system 10, including the valves 49, 50,51 and 52, controls the delivery of air, oxygen and steam from theretorts to the condenser, and the unabsorbed air and the steam` andoxygenl which is mixed with air from the exhaustl or waste pipes 48, and48.

In the present instance automatic means is provided for operating inunison the valves grouped at 7 and 10, opening and closing them andcontrolling the timing and sequence of their operation. l

Referring to Fig. 7, which is an assembly on a large scale of theessential features of each individual valve is operated, the entiremechanism of each valve is inclosed within a casing 53 and each valve,in the form of the invention shown, is operated by a transversecentrally-pivoted lever 54 having a .pin and slot engagement at each endwith one of the cores 55 of two solenoids 5.6, one for each instance, istripped by an upright'stud 58 with which each core is provided. Thevalvemechanism is s o arranged that when there is no current, it is inequilibrium and stationary.A As soon as one coil is energized, the corewhich coperates with that coil is drawn up, the corresponding end of thelever 54 is lifted, ythe lever is swung about its pivot and the valveopened or closed as the case may be. As the core moves -up toward theend of its normal stroke, the stud or pin 58 comes in contact with aroller 59 on the trigger 57 and ,breaks the circuit by swinging thetrigger about its center 60 and moving the end of the trigger at 61 fromthe contact point 62 on the frame; at the same time, the other triggeris released and falls into contact. In this way, the circuits of the twosolenoids are made and broken alternately in accordance with the timingof the controller, the triggers being returned by gravity to normalwhich is the closed circuit position.

lln Figs. 5 and 6, I have illustrated the ,controller and showndiagrammatical'ly the plan of the circuit by means of which thesolenoidsoperating their respective valves are energized in turn to openand close the valves in the desired sequence. lTo this end,

-each-x to `close the corresponding switch and keep the follower incontact with the cam. Each of the cams has a circular periphery 67broken by a shortdepression or recess 68.

the electrical appliance by means of which When a roller or followerenters the recess 'of its cam, the spring 66 closes the switch and thecurrent passing through the circuit energizes the correspondingsolenoids and operates the valves. There are six of the cams 65 shown inoperative'connection with the circuitand two extra cams not connected,shown as mounted on the single cam sha-ft 69. The cams are set ata'suitable angle and the shaft is operated by means of a .motor 70connected to the shaft 69 by means'of toothed gears 71 and 72. T e motorin turn is supplied withcurre t from any suitable source by way ofconnections 73, and driven at a constant speed. Shown as shunted acrossthe motor at 74, there is a coil 75 which, when the circuit 73 isenergized, supports` the core 76 which carries a for a short time whenthe main current is oil'. In this way the excessive losses' which mightresult from interruption of the circuit are avoided. c

Referring to Fig. 5, the solenoids, two for,

each. valve, are for convenience numbered according to the correspondingvalves. 1n the arrangement shown, the left-hand coil a in each instance,when energized, serves to open the valve, and theright-hand coil t toclose it.l In Fig. 5, the circuit is shown diagrammatically. The,diagram includes a main 80 to which each solenoid is connected.

This wire is grounded at 81. The switches 63 are distinguished as 63",632, 633, 634, 63,

and 63". The switch 63', as shown, is connected by a wire 82 `to theclosing solenoid b of the valve 51; the switch 632 is connected to amain 83 which in turn is connected to the opening'solenoid of valves 42,45 and 52 and to the closing solenoids b of the valves 43 and 44; theswitch 633 is connected to a main 84 which is in turn connected to "theopening solenoid a of valve 50 and the closing solenoid Z) of valve 49;the switch 634 is.connected to the closing solenoid Z2 of valve 50; swith 635 is connected to a main 86 from wh' there are leads to the openingsolenoids a of valves 43, 44 and 49 and `to the closing solenoids b ofvalves 42 and 45;`and switch 63 is connected to a main 87 from whichthere areklteads to the opening solenoid@ of valve 51 and the closingsolenoidl b of valve 52.` i l In explaining the operation of the valves,the retorts and the superheating coilsfvit will be assumed that thechemicals in the retorts 9 of the first or left-hand unit, are beingregenerated. The air used is heated in the coil 3 so that it will notcause condensation o'f the steam when the process is reversed, and steamis passed through the same pipes and retorts. AThe heated air from/ thecoil 3 -is led through the superheating coil 4 and by way of the pipe 8through the retorts 9 and out bythe delivery pipe lto the waste orexhaust 48. At the same time steam is being passed from the source byway of the pipe 38 to the superheater 4 and thence through the retorts'9where it takes `upoxygen and passes by way of the delivery pipe 15 tothe pipe 47 and by way of the pipe 16 to the condenser.

When the chemicals in the retorts 9 have(3 and found to be in accordwith the most ef" icient operation, the paths of the steam and weremixed with the supply of. oxygen,v

would so dilute the product as to destroy its commercial value, it isnecessaryy to displace the air content of this portion of the systemwith steam before the product is turned into the regular channel, and tothis end, the air and the steam which first traverses the retorts andpassages must be permitted to escape from the exhaust 48.

To bring about the first condition described, in which air is passingthrough the coil 3, the steam superheating coil 4 and the retort 9,escaping through the exhaust 48, and steam throughv thecoil 4 and theretorts 9', passing by the delivery pipes 15 and 16 to the condenser,the valves 44, 49, 43 and 90 y' 51 areopen and the valves 42, 45, 50 and52 are closed. During this operation, as has been previously pointedout, the material in the retorts' 9 is being oxidized and that in theretorts 9 reduced, the waste air from 9.5

which the supply of oxygen has been taken escaping at 48, and the steamwith the oxygen which has been -produced being carried to the condenserfrom the retorts 9 by way 7 of the pipes 15 and 16. 100

1n the next condition of operation, steam is passed through thesuperheating coils 4 from the retorts 9, taking up oxygen from theregenerated materials in the retorts 9,

and air is led by way of the coils 3 and 4 105 'through the retorts 9and back to the open `air through the exhaust 48.

In order to prevent the air which is left in the retort 9 and the pipesformingpart ofthe first unit yfrom entering the container with the oxy-110` gen, it is necessary to displace all the air in this part of thesystemoby meansl of the entering steam, and todo this, not only the aircontent of the system but a portion of the steam is permitted to escapeinto the open air by way of the exhaust opening 48, so that the nextoperation of the valve systems merely alternates or interchanges thepaths followed by the steam and air in the two units up to where the twocurrents enter the pipe 48, and for a short period both units exhaust byway of the waste openings 48 and 48 respectively. Therefore, inthe nextposition of the valves, 42, 52, 45 and 49 are open and 43, 44, 50 `and51 are closed. 125

During this operation, as stated, the steam and air from the retorts 9and the pipes of the iirst or left-hand unit, are escaping through thewaste opening48.

When the air has been cleared from the rEhe steam 'lo retorts and pipesin theirst system, Which occupiesbut afevv seconds, the position of thevalves must be changed so as to terminate the flow from the Waste 48 andadmit the steam and oxygen to the delivery pipe. 16, so that after thelapse of a comparatively short period, thevalve 49 is closed and thevalve 50 opened.

rl`helourth voperation corresponds to the second, that is steam isturned into the retorts 9Iand air into the retorts 9, the

CIE

passed through the retorts9.

air escaping from the Waste 48 and for the first part of the period,steam and air from the retorts 9 escape by Way of the Waste 48. ln thefourth position of the valves Which gives this operation, the valves 44,49, 43 and' 52 are open vand valves 42, 45, 50 and 51 arefclosed. Underthese circumstances, air heated in the coils 3 and 4 is passed throughthe retorts 9 and out ot the Waste opening 49, regenerating the chemicalin the retorts 9, and steam from the source 5, superheated in the coils4, is Fora short period, itis necessary to blow out the steam. and airfrom these retorts to prevent pass. ing the air into the oxygen whichJforms the product, and for this reason the steam, onyn gen and air fromthe retorts 97 are permitted to escape from the outlet 49, but after avery short' tirne the escape of the steam and oxygen trom the Waste 49must be terminated andthe product passed by Way oi'- thedelivery 16 tothe condenser, so that the next operation, which takes place almostimmediately consists in `the closing of the valve 52 and opening ofthe-valve 51.

As has been fully described in connection with the Wiring diagram, Fig.5, there is a series of switches 63 operated by a series of cams 67controlling a series of solenoids, one to open and one to close eachvalve. Each switch controls a single solenoid or a group of solenoids,connected in parallel, as the case may be. p Where a number ofoperations, either opening or closing take place simultaneously in everyinstance, thelcorrespending coils are connected in parallel andcontrolled by a single svvitchoperated by a single cam. lin connection'with the tWo units shovvn, there aresix different groups or sets ofoperations requiring that the solenoids be connected in six groups 4sothat there are six switches and six cams shown on' a single shaft; TheWiring diagram and analysis of the valve operations show that in thepresent instance, the valves 49,y 43 and 44 are opened and the valv'es42 and 45 are closed'simu'ltaneously. The valves 42,

45` and 52 are opened and the valves 44` and 43v are closedsimultaneously. The

valve ,50 is opened and the valve 49 closed simultaneously in' eachinstance. The valve 52 is closedand the valve 51 opened simulL taneouslyin each instance.' 'lhe valves 5J.r

'leading from the bottom chamber.

and 50 are separately operated in closing and vrequire each a separatecam and separate switch. Each set of simultaneous operations V1saccomplished by a single cam and switch as shown.

It Will thus be apparent that the passage of steam and air through theapparatus When once determined as to time and sequence, can belconveniently accomplished as described andr can be repeatedindeiinitelywith absolute regularity, so that a product of uniform and maximumpurity can be prodnced.

rllhe mined steam and oxygen from the retorts is led by vvay of thedelivery pipe 16 to the condenser l? vlhere the mixture is cooled andthe steam condensed and drawn ohio/in the form olf Water. The condenserillustrated is particularly adapted tor use in connection with thisprocess in that the cooling eil'ect resulting from av continuous supplyor Water 1s obtained Without bringing the product 'in contact With theWater,

are connected by small tubes l@ and the 'intermediate space around thetubes and between, the headers 91 is filled with Water, supplied by Wayof .the pressure pipe 93, and led o from the condenser byrvay of theoverflow 94, the latter shown as of considerably greater capacity thanthe supply pipe 93 having its intake just belovv the top header 91. Thegas pipe 16 from the retorts enters the top chamber and the gas isWithdrawn by'-tvay ot the pipeT 19 condensed Water/is removed from thebottom of the condenser by' Way of a suitablel drip pipeI 98 and boththe drip pipe 98 and the outlet pipe 94. for the cooling Water areprovided With .vvater'l seals 96` and '97 respectively to prevent accessof air to the condenser). The Water seal 96 prevents the lovv of.air'directly into the gas chamber.

The`seal`97 is to prevent the access of air to the cooling Water space.This is provided in vievv ofthe fact that a slight f vacuum is set upvin the-'gas space. of thev and With anyv considerable condenser y'amount of air in the cooling Water space, a leak 1n the condenser wouldadmit a1r to v the gas and cause serious loss of value in ythe'product.

Thel functions of the valves 22, 23, 26 and 28, the gasometer20 and thedrip 2o will be understoodfby-those skilled in. the alt Per;

las

v oxygen under pressure.

.compression will also be understood and the details of therefrigerating'apparatus already described in a general way, are not ofimport-ance .in connection with this 4disclosure. a

As I have stated, Fig. 1 is not an actual -view of `-any known form ofthe apparatus. vIt is merely a diagram showing the relation in which thecoils and retorts are connected to each other and to the manifolds 35,36,39 and 40 and the manifold 47. No actual view of the apparatus as setup would show the relation 4of these parts to advantage, but in Fig. 1anelement ofythe apparatus associated immediately with the retorts andcoils 3 and 4 is not shown. Each unit or set of coils and retortsisinstalled in a suitable furnace by which the air and steam are broughtto the temperature at which they maybe used to the best advantage inreducing and regenerating the chem- `icals used. Two furnaces combinedin the relation in which they would be used for heating the two umtsdescribed are' shown in transverse cross section in Fig. 3 and alongitudinal section through one furnace is shown in Fig. 4. The batteryof furnaces illustrated in Fig. 3 comprises two combustion chambers 100and 101, each having a grate 102 and being surmounted by aireybrick arch103. In the form of the invention shown, a forced draft is used, the airbeing drawn from the ash pits 104 'through the grate, outward laterallythrough an` opening 105 into a chamber 106 in which? are located theretorts 9 and 9. From-this chamber hot gases pass into a second chamber10S in theI left-hand unit and 109 in the right-hand unit. The chamber108 contains the air heating coil 3 and steam superheating coil 4and'inthe chamber 109 is a steam superheating coil 4. The products ofcombustion are exhausted through a stack or suitable exhaust opening110.

Fig. 4, as shown, is a section on the line 4, 4 of Fig. 3. By referenceto this ligure it will be seen that the exhaust opening 110 is connectedto a chamber at the rear of the v` furnaces, indicated at 111, which inturn leads vto the damper and flue by way ofian opening 112. Thischamber is surmounted by an riron plate 113 anda grid 114 by means ofwhichthe exhaust gases are utilized in the preparation of thepermangan'ate vused in the retorts. y By heating a mixture of oxid ofmanganese and caustic soda in this way, the permanganate used in theremaracas torts may be preparedin a convenient and economical manner,and this apparatus may be utilized in reclaiming the exhausted ma;terirals.,

lThe operation of theentire apparatus has 'agency are avoided. ln thiswayA I not only t avoid loss but am enabled to produce oxygen of auniform degree of purity at a cost much reduced as compared to the costpre viously involved in the practice of similar methods and less thanthat of the existing electrical and compression methods. Im-

provements in the other features have elimi- Y natedother sources ofloss and as a result, a method of manufacture which has recently beenconsidered capable of use only in a laboratory, is ,made commerciallyavailable.

1 have described in detail numerous features of my apparatus which arenot essential to the invention in order that the disclosure may besufficiently full and complete to enable those skilled in `the art tobuild the apparatus and operate it.v However, I do not desire to limitmyclaims to the'specific details described. i. v

What I claim and desire-to secure by Leti ters Patent is:

1. In'an apparatus for makingoxygen by decomposition and regeneration ofan oxy# gen compound, a retort for the oxygen compound, means forheating the retort, means for passing heated air and superheated steamalternately through the retort, valves for alternating the path of theair and steam and automaticmeans for operating the valves, equalizingYthe period and maintaining the sequence of operation.

2. In an, apparatus for making oxygen byL decomposition andlregeneration of material ico containing oxygen, a plurality of retortsfor the material containing oxygen, means for leading' heated air andsuperheated steam alternately to the retorts, a manifold, meansconnecting the-retortsv to the manifold, a condenser, means connectingthe manifold to the condenser,ran exhaust outlet for the manifold,valves in themanifoldI for controlling the passages from the retorts,and automatic means for operating the valves anddetermining theirsequence of operation whereby steam and oxygen are led to the condenserand the air is permitted to escape.

3. In'an apparatus for making oxygen by the decomposition andregeneration of an oxygen compound, retorts for the oxygen compound, anexhaust manifold, pipes leading from each retort tothe exhaust manifold,a condenser, a pine leadii-g from that manifold to the condenser, asupply manifold, means for superheating steam and air and leading themto the retorts, means in the supply manifold for controlling thepassage` of steam and airto the retorts whereby the retorts arealternately supplied with superheated steam and hot air, valves in theex* 'haust manifold, and automatic means for the paths of the air andsteannland automatic means for operating said means, equaliaing theperiod and maintaining the se quence of operation. l 1

5. ln an apparatus for malring oxygen by decomposition and regenerationof an oxygen compound, retorts for the oxygen compound, means forheating the retorts, means for passing heated air and steam alternatelythrough the retorts, means for alternating the path of the yair andsteam, automatic means for operating said means, equalizing the periodand maintaining the sequence of operation, a condenser, a compressor andrefrigerating means for cooling the gas after it has been compressed.

6. ln an apparatus for making oxygen by 'decomposition and regenerationof an oxy-V gen compound, a retort for the` oxygen compound, means forheating the retort,

means for passing heated 'air and steam all-Lv ternately through theretort, nieansfor alternating the path of the air and'steam, automaticmeans for operating said means, equalizing the period and maintainingthe sequence of operation, and a condenser, having means for preventingthe access of 1the Water to the gas space.

7. In an apparatus for making oxygen by decomposition and regenerationof an oxygen compound, a plurality'o'fretorts, steam superheating means,means for heating air, a delivery manifold, delivery pipes .leadingfrom7 the retorts to said manifold," a condenser, means for-leadingmixed steam and oxygen from the delivery manifold tothe condenser, wasteoutlets in the delivery manifold, a valve controlling each deliverypipe, valves and automatic means for actuating the valves to control thesteam and air passages to alternate the flow of air and steam throughthe retorts and to permit the escape of the waste air and to lead themixed steam and oxygen to the condenser, the valves and actuating meansbeing arranged to cause the initial flow of steam in each instance toblow the air out/of the re torts by Way of the waste. 8. An apparatusfor making oxygen consisting of a plurality ofretorts and means forheating them, aV delivery manifold l() and a steam and air controllingmanifold 7, air heating means and steam heating means for each retort,delivery pipes connecting the delivery manifold to the retorts, acondenser, means for leading the product from the delivery manifold tothe condenser,

means connecting the air heating coil and each steam heater to thedistribu ion manifold and each steam heater` to the correspondingretort, valves in the delivery manifold controlling each delivery pipe,exhaust outlets from the delivery manifold, a valve controlling yeachexhaust outlet, and valves in the distributionlinanifold controlling thesteam` and air passages, and automatic means for opening and closing the`valves and controlling the sequence of their operation to lead steamand air alternately to the retorts, to exhaust the waste (air from thedelivery manifold and lead mixed oxygen and steam to 'the condenser, thevalves being timed to provide for the blowing out through the exhaust ofthe waste air from each retort during theinitial portion of the steamnow.

9.,ln an apparatus for making oxygen by decomposition and regenerationof an oxygen compound, retorts for the oxygen compound, means forheating the retorts,

means for passingheated air and supern heated steam alternately throughthe' retorts, valves for alternating the path of the air and steam,automatic means for operating the valves, equalizing the period andmaintaining the sequence of operation, said means being electricallyoperated, ,the circuit including a coil connected to each valve,

means for controlling the electrical condition of each coil and a motorfor operating said means.

l0. ln an apparatus for making oxygen by decomposition and regenerationof an oxygen compound, a retort for the oxygen compound, meansl forheating the retort, means for passing heated air andy superheated steamalternately through the retort, valves for alternating the path of theair and steam, automatic means for operating the valves, equalizing theperiod and maintaining the sequence of operation, sa1d means beingelectrically operated, two coils for each valve, means for connectingthe coils to the valves, one coil serving to open and the other to closethe corresponding valve, a source of electricity .and connectionswhereby the coils are connected in groups, a switch for each group tooperate thecoils lsteam alternately through the retorts, valves foralternating the path of the air and steam, automatic means for operatingthe valves, equalizing the period and maintaining the sequence ofoperation, said means being electrically operated, a plurality of coilsfor each valve, means for connecting the coils to the valves, each tooperate the valve when the core is energized, one coil serving to openand the other to close the corresponding Valve', a source of electricityand `connections whereby the coils operating the respective valvessimultaneously are connected in groups, a switch for each group, a camoperating each switch, a single shaft upon Which the cam is mounted, anelectric motor connected to the shaft to rotate it, the motoroperatingat a constantspeed.

` 12. ln an apparatus for making oxygen Lwaoaa by decomposition of anoxygen compound, a plurality of retorts for the oxygen compound, means-for leading heated air and t manifold, pipes leading from each retortto the delivery manifold, valves inthe de-V livery' manifold controllingthe exhaust and the passage to the container, valves in theY supplymanifold and Ymeans for controlling the valves, those in the"a supplymanifold so i that the air passage l1s closed before the v`steacmpassage is opened, and those in the delivery manifoldso that the exhaustis closed before the passage to the container is opened, said means alsocontrolling the passagesto pass air and steam alternately through therespective retorts. Q A, 4Signed by me at Baltimore, Maryland, this 24thday of May, 1915.

BENJAMINH. CRAM.

Witnesses: l u

EDWARD L. HASH, y ALICE G. DONEGAN. l

